


Area Forecast Discussion
Issued by NWS Charleston, SC
Issued by NWS Charleston, SC
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173 FXUS62 KCHS 272333 AFDCHS Area Forecast Discussion National Weather Service Charleston SC 733 PM EDT Wed Aug 27 2025 .SYNOPSIS... Expect dry and cool conditions as high pressure prevails through Thursday. Thereafter, a stationary front should remain to the south of the region through the weekend, and cause for unsettled conditions to return on Friday. && .NEAR TERM /THROUGH THURSDAY/... Upper level cirrus will increase tonight from west to east as another shortwave begins to move across the region, with temperatures diurnally cooling into the mid 60s inland and mid 70s along the coast. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/... At the surface, high pressure will start to erode on Thursday as a mid-lvl trough situated over the Great Lakes begins to strengthen and shift southeastward towards the region. Simultaneously, a weak low located over the Northern Gulf could develop and move slowly across the Florida Peninsula with a frontal boundary. This low should move offshore by Friday morning as this frontal boundary remains to the south through the weekend. This will increase the chances for precipitation on Friday and Saturday, with PoPs peaking 50-70% on Saturday afternoon. It`s still uncertain how much coverage there will be as it`s very dependent on the evolution of this low. However, the severe threat remains low as instability looks limited, but brief locally heavy rainfall is still possible. WPC has highlighted the region under a Marginal Risk (level 1 of 4) for excessive rainfall for both of these days. Expect temperatures to reach into the mid to upper 80s on Thursday and Friday, and a low 80s on Saturday due to increased cloud/precip. chances. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As an amplified upper-lvl trough centers itself over the Eastern CONUS, causing possibly multiple shortwaves to pass through the region allow unsettled conditions to continue through early next week. Yet again, WPC has placed the region under a Marginal Risk (level 1 of 4) for excessive rainfall for Sunday. Additionally, another weak low pressure could form offshore early next week and continue on the onset of unsettled conditions. However, confidence remains low for the early part of next week as models continue to highly differ, but hopefully this improves in the next forecast cycle. Temperatures will be slightly below normal for this time of year. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... VFR. Extended Aviation Forecast: VFR conditions expected to largely prevail, with brief periods of flight restrictions possible by the end of the week as chances for showers/thunderstorms increase. && .MARINE... Surface high pressure will continue to linger across the marine zones into tonight. Winds should generally favor a northeast direction at around 10 kts. Seas should range around 2 ft. Beyond 40 nm from shore, seas could approach 3 ft at times. Near and offshore waters from Savannah GA to Altamaha Sound GA have a chance (20-30%) for scattered showers and thunderstorms continuing into the overnight hours. Thursday through Monday: As surface high pressure dominates the forecast, a weak area of low pressure located in the northern Gulf could move across the Florida Peninsula along a frontal boundary and then shift offshore by Friday morning. This frontal boundary should stay to the south of the region. Expect east-northeasterly winds to remain across the Atlantic until early next week. It could become quite gusty on Sunday and Monday as another low tries to potentially develop offshore early next week. Otherwise, no marine concerns are anticipated through this period. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$ NEAR TERM... SHORT TERM...Dennis LONG TERM...Dennis AVIATION...Dennis MARINE...APT/Dennis